My cat Tommie had to go to the vet recently, because he was drooling and had a very bad odour from his mouth. He did eat and drink, but only small amounts. He wasn't his perky self, but who would be if you have a tooth ache?
Well he indeed has some bath teeth, but they're most probably caused by kidney problems. So the vet wants him on a renal diet. And that's where we encounter a new problem: my cat is very allergic to pork, and most brands (like Royal Canin) put some form of pork in their renal diet.
Some brands (like Hill's) use 'animal products' in their food, but won't disclose which animals are used. So it could be pork, it could be safe, but I won't bet his health on it. He stole a sample pack of Trovet renal diet, and got very sick (vomiting, diarrhea, incontinence). Had to get him back to vet again, because now he also didn't want to eat anything.
I did find a brand without pork, but it uses milk. Adult cats are by default lactose intolerant, and Tommie is very lactose intolerant. So, that's a no-go, too.
I tried for years to get him to eat BARF, but he refuses it and prefers his kibble (Applaws, 80% meat, no grains) and canned food (Feringa, 96% meat and organs, no grains), the closest I can get to BARF with him.
So, my question to you, fellow GetBigger and animal lover: do you know a brand of renal diet for cats, that does not contain any traces of pork and/or milk?